WooCommerce Product Bundles 8.1.2

* Tweak - Fix fatal error when exporting products via WP-CLI. Bundled item data cannot be exported via WP-CLI.

* Fix - Update in-house WP 5.3+ select2 styles for WC 3.8.1 compatibility.

* Tweak - Replaced selectWoo with self-maintained flavor of select2.
* Tweak - Minor styling tweaks for WordPress 5.3.
* Tweak - Fix variable bundled item 'for' attribute.
* Fix - Parent product always included in bundled variation search results due to a bug in WooCommerce search.